<div class="row">
  <div class="col-xs-3">
    <div class="list-group">
      <a href="#" class="list-group-item active">
          图片过滤
      </a>
      <a routerLink="jpg" class="list-group-item">JPG</a>
      <a routerLink="gif" class="list-group-item">GIF</a>
    </div>
  </div>
  <div class="col-xs-9">
    <router-outlet></router-outlet>
  </div>
</div>